Conventional strings for sport rackets are arranged in altitude and longitude directions in the racket head and the strings are pulled to have proper tension such that when the racket hits the ball, the ball flies powerfully and quickly. The strings are pulled by string clamping device while the racket head is securely positioned. The string clamping device is located lower than the racket head so that the racket head does not hit the string clamping device when the racket head rotates in order to string the strings in different directions. However, the lower positioned string clamping device is located lower than the string holes in the racket head pulls the string an angle so that the string is bent at the periphery of the opening of the string hole in the outer side of the racket head. The string might be damaged at the bending point and the periphery of the string holes at the bending point of the string generates a force which may affect the value of tension of the strings.
The present invention intends to provide a string clamping device which pulls the strings straight without any bending points so that the tension of the string is precisely set.